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VEGETATION DYNAMICS AT DIFFERENT SPATIO-TEMPORAL SCALES IN FREQUENTLY BURNED MIXED CONIFER FORESTS, NORTHERN SIERRA NEVADA RANGE, CALIFORNIA.
Title
VEGETATION DYNAMICS AT DIFFERENT SPATIO-TEMPORAL SCALES IN FREQUENTLY BURNED MIXED CONIFER FORESTS, NORTHERN SIERRA NEVADA RANGE, CALIFORNIA.
Creator
Paudel, Asha, Markwith, Scott H., Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
Abstract/Description
Mixed conifer forests in the Sierra Nevada, California, face threats from frequent highseverity fire associated with climate change and fuel accumulation leading to vegetation shifts at local and landscape scales. Under rapid climate change, a clear understanding of how vegetation responds to single and/or repeated wildfires is still lacking and needs to be investigated. Using field and satellite data, the effects of wildfire on vegetation dynamics were explored at the plot and landscape...
Show moreMixed conifer forests in the Sierra Nevada, California, face threats from frequent highseverity fire associated with climate change and fuel accumulation leading to vegetation shifts at local and landscape scales. Under rapid climate change, a clear understanding of how vegetation responds to single and/or repeated wildfires is still lacking and needs to be investigated. Using field and satellite data, the effects of wildfire on vegetation dynamics were explored at the plot and landscape levels in this dissertation project. Results from the field data suggest that management activities may be required in high-severity burned areas to restore dominance of mixed conifer forests and regain historical species composition in areas where live trees persist. Results from satellite data suggested that large shrub patches, created after mixed severity fire, fragment the homogenous mixed conifer dominated forest of the Sierra Nevada to create a more heterogeneous landscape, however the extent of diversity and fragmentation were dependent on fire severity and scales. Natural wildfires may restore landscape heterogeneity to conditions equivalent to the pre-Columbian era, but effects under the projected climate change scenario for 21st century remain uncertain. Mixed conifer dominated forests are predicted to be the dominant component of the Sierra Nevada landscape under historical fire probabilities and excluding higher probability of high-severity fire over the next 100 years.
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Date Issued
2022
PURL
http://purl.flvc.org/fau/fd/FA00013966
Subject Headings
Vegetation dynamics, Climate change, Fire ecology, Wildfires--Management
Format
Document (PDF)
BIODIVERSITY, CARBON, AND WILDFIRES IN FOREST ECOSYSTEMS: EXAMINING DEAD WOOD’S INFLUENCE BY INTEGRATING META-ANALYTIC, HIERARCHICAL & SIMULATION MODELING APPROACHES
Title
BIODIVERSITY, CARBON, AND WILDFIRES IN FOREST ECOSYSTEMS: EXAMINING DEAD WOOD’S INFLUENCE BY INTEGRATING META-ANALYTIC, HIERARCHICAL & SIMULATION MODELING APPROACHES.
Creator
Parajuli, Rabindra, Markwith, Scott H., Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
Abstract/Description
Forest ecosystems are critically important to biodiversity and the global carbon budget. Within forest ecosystems, dead wood has several ecological roles, including in carbon and nutrient dynamics and biodiversity conservation. However, surface fuels in forests also influence wildfire behavior and associated risks and hazards. Therefore, appropriate management of dead wood contributes directly to appropriate functioning of the forest ecosystem by conserving forest biodiversity, mitigating...
Show moreForest ecosystems are critically important to biodiversity and the global carbon budget. Within forest ecosystems, dead wood has several ecological roles, including in carbon and nutrient dynamics and biodiversity conservation. However, surface fuels in forests also influence wildfire behavior and associated risks and hazards. Therefore, appropriate management of dead wood contributes directly to appropriate functioning of the forest ecosystem by conserving forest biodiversity, mitigating extreme wildfire events and pyrogenic emissions, and enhancing carbon sequestration. Using data extracted from peer-reviewed journal articles, geospatial, and field inventory data, and integrating meta-analytic, hierarchical regression, and vegetation simulation modeling approaches, this dissertation project examined the influence of dead wood on biodiversity, carbon, and wildfires in forest ecosystems. The meta-analysis results suggest that dead wood quantity is an indicator of forest biodiversity, while dead wood types and decay stages had varied relationships with biodiversity. Generalized linear and additive mixed effects modeling of geospatial and human observed data demonstrated the predominant influences of weather conditions and moderate effects of live and dead fuels on exceptionally large wildfires’ behavior in the western United States. Consistently dominant effects of temperature on wildfire behavior highlight and emphasize the pressing need to address climate change's impact on western US forests. Lastly, vegetation and wildfire simulation modeling of forest stand inventory data and post-modeling carbon computations suggested that physical harvesting of dead wood, an approach analogous to traditional practice of firewood collection, when combined with modern mechanical fuel reduction treatments in Sierra Nevada, CA, mixed conifer forests has great potential to mitigate wildfire hazards, reduce fire emissions, and enhance carbon sequestration.
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Date Issued
2024
PURL
http://purl.flvc.org/fau/fd/FA00014456
Subject Headings
Forest ecology, Wildfires, Forest management, Forest biodiversity conservation
Format
Document (PDF)
SPATIOTEMPORAL DYNAMICS OF THE FLORIDA BAY ECOSYSTEM IN RELATION TO CLIMATE CHANGE AND EVERGLADES RESTORATION
Title
SPATIOTEMPORAL DYNAMICS OF THE FLORIDA BAY ECOSYSTEM IN RELATION TO CLIMATE CHANGE AND EVERGLADES RESTORATION.
Creator
Smith, Mason J., Markwith, Scott H., Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
Abstract/Description
One of the largest restoration programs in the world, the Comprehensive Everglades Restoration Plan (CERP) aims to restore freshwater flows to the Everglades and Florida Bay estuary. Coupled with climate change, future changes from restoration highlight the need to implement an ecosystem-based fisheries management (EBFM) approach in Florida Bay. The Ecopath framework was used to develop and apply a mass-balanced food web model to the spatiotemporal dynamics of hydrological restoration and...
Show moreOne of the largest restoration programs in the world, the Comprehensive Everglades Restoration Plan (CERP) aims to restore freshwater flows to the Everglades and Florida Bay estuary. Coupled with climate change, future changes from restoration highlight the need to implement an ecosystem-based fisheries management (EBFM) approach in Florida Bay. The Ecopath framework was used to develop and apply a mass-balanced food web model to the spatiotemporal dynamics of hydrological restoration and climate change through time. Results suggest Florida Bay is stabilized through large detrital energy pathways and low nutrient inputs, but subject to species distribution shifts due primarily to sea-level rise and salinity variation. A suite of winners and losers predicted provide an opportunity to ensure management strategies are designed appropriately to best achieve desired results for the future of the Florida Bay ecosystem.
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Date Issued
2022
PURL
http://purl.flvc.org/fau/fd/FA00013913
Subject Headings
Florida Bay (Fla.), Restoration ecology, Climate change
Format
Document (PDF)